When we finishing up shooting the "Archer's Paradox" video with Byron Ferguson, he decided he wanted to test out a new broadhead design by shooting it into a cinder block.  he had no idea at the time what was going to happen, and he asked me to film it with the high speed camera (which I did).  Here are the photos of the aftermath.  As you can see, the arrow stuck into the cinder block without damage.  The arrow head came unglued from the shaft of the arrow, but nothing broke.  I was pretty blown away by the results.  Byron has these broadheads made in Austria and sells them on various websites like this one.